Casing check valve

ABSTRACT

A casing check valve for providing isolation of an open hole section of a wellbore from a cased hole section of the wellbore is described herein. The casing check valve can include a housing and an actuating sleeve movably disposed within the housing between an actuated position and a normal position. The housing can include a housing body, at least one actuating sleeve coupling feature, a flapper assembly, a flapper seat, and at least one casing pipe coupling feature. The actuating sleeve can include an actuating sleeve body, at least one housing coupling feature, at least one operating tool coupling feature, and a distal extension.

TECHNICAL FIELD

The present application relates to casing valves, and in particular, methods and systems of mechanically-operated casing check valves.

BACKGROUND

The drilling of an oil, gas, or other type of well requires that an upper casing string be set at some shallower depth than the total depth of the well. Some purposes of the casing string are to protect a portion of the wellbore environment and to protect personnel. When the casing string is set, the drilling operation continues to extend the open hole portion of the wellbore below the casing string. During the drilling process, it can be necessary to pull the drill string (also called the tubing string) out of the wellbore (a process known as “tripping”) on one or more occasions. The open hole and casing provides a hydraulic conduit up through the wellbore that serves as a flow path with the potential risk of flow, which can jeopardize the integrity of the wellbore and/or present safety concerns. In other words, unless a tripping operation is carefully controlled, the integrity of the open hole can be compromised.

A drill string can be several thousand feet long, and so performing a tripping operation can take many hours. This time to perform a tripping operation, as well as a subsequent reinsertion of the drill string into the wellbore, can cost significant amounts of money without making any progress in terms of extending the open hole portion of the wellbore. Consequently, it is undesirable to slow the tripping process from a financial perspective.

SUMMARY

In general, in one aspect, the disclosure relates to a casing check valve for providing isolation of an open hole section of a wellbore from a cased hole section of the wellbore. The casing check valve can include a housing and an actuating sleeve. The housing of the casing check valve can include a housing body forming a housing cavity that traverses therethrough, where the housing body includes a top portion, a middle portion, and a bottom portion. The housing of the casing check valve can also include at least one actuating sleeve coupling feature disposed on an inner surface of the middle portion of the housing body. The housing of the casing check valve can further include a flapper assembly disposed along the inner surface of the bottom portion of the housing body. The housing of the casing check valve can also include a flapper seat disposed on the inner surface of the bottom portion of the housing body adjacent to the flapper assembly. The housing of the casing check valve can further include a first casing pipe coupling feature disposed on the top portion of the housing body, where the first casing pipe coupling feature is configured to couple to a first casing pipe. The actuating sleeve of the casing check valve can be disposed within the housing cavity between an actuated position and a normal position, where the actuating sleeve is concentric with and adjacent to the housing. The actuating sleeve of the casing check valve can include an actuating sleeve body forming an actuating sleeve cavity. The actuating sleeve of the casing check valve can also include at least one housing coupling feature disposed on an outer surface of the actuating sleeve, where the at least one housing coupling feature is removably coupled to the at least one actuating sleeve coupling feature of the housing as the actuating sleeve moves between the actuated position and the normal position. The actuating sleeve of the casing check valve can further include at least one operating tool coupling feature configured to receive a complementary coupling feature of an operating tool disposed within the actuating sleeve cavity. The actuating sleeve of the casing check valve can also include a distal extension that extends from a distal end of the actuating sleeve body, where the distal extension opens the flapper assembly when the actuating sleeve is in the actuated position, and where the distal extension allows the flapper to close when the actuating sleeve is in the normal position.

In another aspect, the disclosure can generally relate to a casing check valve system for providing isolation within a wellbore. The system can include a casing string disposed in a wellbore, where the casing string includes a number of casing pipe. The system can also include an operational string comprising an operating tool, where the operating tool includes at least one complementary coupling feature. The system can further include a casing check valve coupled to a first casing pipe, where the casing check valve can include a housing and an actuating sleeve. The housing of the casing check valve can include a housing body forming a housing cavity that traverses therethrough, where the housing body includes a top portion, a middle portion, and a bottom portion. The housing of the casing check valve can also include at least one actuating sleeve coupling feature disposed on an inner surface of the middle portion of the housing body. The housing of the casing check valve can further include a flapper assembly disposed along the inner surface of the bottom portion of the housing body. The housing of the casing check valve can also include a flapper seat disposed on the inner surface of the bottom portion of the housing body adjacent to the flapper assembly. The housing of the casing check valve can further include a first casing pipe coupling feature disposed on the top portion of the housing body, where the first casing pipe coupling feature couples to a first casing pipe of the casing pipe. The actuating sleeve of the casing check valve can be disposed within the housing cavity between an actuated position and a normal position, where the actuating sleeve is concentric with and adjacent to the housing. The actuating sleeve of the casing check valve can include an actuating sleeve body forming an actuating sleeve cavity, inside of which the operational string is disposed. The actuating sleeve of the casing check valve can also include at least one housing coupling feature disposed on an outer surface of the actuating sleeve, where the at least one housing coupling feature is removably coupled to the at least one actuating sleeve coupling feature of the housing as the actuating sleeve moves between the actuated position and the normal position. The actuating sleeve of the casing check valve can further include at least one operating tool coupling feature that receives the at least one complementary coupling feature of the operating tool disposed within the sleeve cavity. The actuating sleeve of the casing check valve can also include a distal extension that extends from a distal end of the actuating sleeve body, where the distal extension opens the flapper assembly when the actuating sleeve is in the actuated position, and where the distal extension allows the flapper to close when the actuating sleeve is in the normal position.

In yet another aspect, the disclosure can generally relate to a method for isolating a section of a wellbore. The method can include receiving a coupling feature of an operating tool. The method can also include repositioning, based on movement of the operating tool in a direction, an actuating sleeve within a housing body from a first position to a second position, where repositioning the actuating sleeve from the first position to the second position changes a flapper assembly from a first state to a second state. The method can further include releasing, based on continued movement of the operating tool in the direction, the coupling feature of the operating tool.

These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate only example embodiments of methods, systems, and devices for casing check valves and are therefore not to be considered limiting of its scope, as casing check valves may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

FIG. 1 shows a schematic diagram of a field system in which casing check valves can be used in a wellbore in accordance with certain example embodiments.

FIG. 2 shows a cross-sectional side view of a casing check valve in a closed position in accordance with certain example embodiments.

FIG. 3 shows a cross-sectional side view of the casing check valve of FIG. 2 in an open position in accordance with certain example embodiments.

FIG. 4 shows another cross-sectional side view of the casing check valve of FIG. 3 in an open position in accordance with certain example embodiments.

FIG. 5 shows a cross-sectional side view of another casing check valve in a closed position in accordance with certain example embodiments.

FIG. 6 shows a cross-sectional side view of the casing check valve of FIG. 5 in an open position in accordance with certain example embodiments.

FIG. 7 shows another cross-sectional side view of the casing check valve of FIG. 6 in an open position in accordance with certain example embodiments.

FIG. 8 shows a cross-sectional side view of yet another casing check valve in an open position in accordance with certain example embodiments.

FIG. 9 shows a flowchart of a method for isolating a section of a wellbore using a casing check valve in accordance with certain example embodiments.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The example embodiments discussed herein are directed to systems, apparatuses, and methods of casing check valves in a wellbore. While the example casing check valves shown in the figures and described herein are directed to use in a wellbore, example casing check valves can also be used in other applications, aside from a wellbore, in which a casing string and/or a need for isolating a section of pipe can be used. Thus, the examples of casing check valves described herein are not limited to use in a wellbore.

Further, while some example embodiments described herein use hydraulic material and a pressurized hydraulic system to operate the casing check valve, example casing check valves can also be operated using other types of systems, such as pneumatic systems. Thus, such example embodiments are not limited to the use of hydraulic material and pressurized hydraulic systems. A user as described herein may be any person that is involved with a field operation (including a tripping operation) in a subterranean wellbore for a field system. Examples of a user may include, but are not limited to, a roughneck, a company representative, a drilling engineer, a tool pusher, a service hand, a field engineer, an electrician, a mechanic, an operator, a consultant, a contractor, and a manufacturer's representative.

Any example casing check valves, or portions (e.g., components) thereof, described herein can be made from a single piece (as from a mold). When an example casing check valve or portion thereof is made from a single piece, the single piece can be cut out, bent, stamped, and/or otherwise shaped to create certain features, elements, or other portions of a component. Alternatively, an example casing check valve (or portions thereof) can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to adhesives, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to fixedly, hingedly, removably, slidably, and threadably.

Components and/or features described herein can include elements that are described as coupling, fastening, securing, or other similar terms. Such terms are merely meant to distinguish various elements and/or features within a component or device and are not meant to limit the capability or function of that particular element and/or feature. For example, a feature described as a “coupling feature” can couple, secure, fasten, and/or perform other functions aside from merely coupling. In addition, each component and/or feature described herein (including each component of an example casing check valve) can be made of one or more of a number of suitable materials, including but not limited to metal (e.g., stainless steel), ceramic, rubber, and plastic.

A coupling feature (including a complementary coupling feature) as described herein can allow one or more components and/or portions of an example casing check valve (e.g., a sleeve) to become mechanically coupled, directly or indirectly, to another portion (e.g., a wall) of the casing check valve. A coupling feature can include, but is not limited to, a portion of a hinge, an aperture, a recessed area, a protrusion, a slot, a spring clip, a tab, a detent, and mating threads. One portion of an example casing check valve can be coupled to another portion of a casing check valve by the direct use of one or more coupling features.

In addition, or in the alternative, a portion of an example casing check valve can be coupled to another portion of the casing check valve using one or more independent devices that interact with one or more coupling features disposed on a component of the casing check valve. Examples of such devices can include, but are not limited to, a pin, a hinge, a fastening device (e.g., a bolt, a screw, a rivet), and a spring. One coupling feature described herein can be the same as, or different than, one or more other coupling features described herein. A complementary coupling feature as described herein can be a coupling feature that mechanically couples, directly or indirectly, with another coupling feature.

Example embodiments of a casing check valve can isolate at least a distal portion of a wellbore, including an open hole within the wellbore, beyond the casing string. The example casing check valve can allow the drill string (also called a tubing string or operational string, positioned within the cavity of the casing string) to be tripped above the example casing check valve with the hydrostatic pressure of the mud column in the cavity of the casing string above the example casing check valve to be equal to, greater than (overbalanced), or less than (underbalanced) the open hole pressure below the example casing check valve. In certain example embodiments, multiple example casing check valves can be part of and/or disposed within the casing string to provide redundancy and/or to isolate various sections of the wellbore that are cased and/or open hole relative to each other.

Example embodiments of casing check valves in a wellbore will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of casing check valves in a wellbore are shown. Casing check valves in a wellbore may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of casing check valves in a wellbore to those of ordinary skill in the art. Like, but not necessarily the same, elements (also sometimes called modules) in the various figures are denoted by like reference numerals for consistency.

Terms such as “first,” “second,” “top,” “bottom,” “end,” “inner,” “outer,” “proximal,” and “distal” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation. Also, the names given to various components described herein are descriptive of one embodiments and are not meant to be limiting in any way. Those of ordinary skill in the art will appreciate that a feature and/or component shown and/or described in one embodiment (e.g., in a figure) herein can be used in another embodiment (e.g., in any other figure) herein, even if not expressly shown and/or described in such other embodiment.

Further, if a component of a figure is described but not expressly shown or labeled in that figure, the label used for a corresponding component in another figure can be inferred to that component. Conversely, if a component in a figure is labeled but not described, the description for such component can be substantially the same as the description for the corresponding component in another figure. The numbering scheme for the various components in the figures herein is such that each component is a three digit number and corresponding components in other figures have the identical last two digits.

FIG. 1 shows a schematic diagram of a land-based field system 100 in which casing check valves can be used within a subterranean wellbore in accordance with one or more example embodiments. In one or more embodiments, one or more of the features shown in FIG. 1 may be omitted, added, repeated, and/or substituted. Accordingly, embodiments of a field system should not be considered limited to the specific arrangements of components shown in FIG. 1.

Referring now to FIG. 1, the field system 100 in this example includes a wellbore 120 that is formed by a wall 140 in a subterranean formation 110 using field equipment 130. The field equipment 130 can be located above a surface 102, such as ground level for an on-shore application and the sea floor for an off-shore application, and/or within the wellbore 120. The point where the wellbore 120 begins at the surface 102 can be called the entry point. The subterranean formation 110 can include one or more of a number of formation types, including but not limited to shale, limestone, sandstone, clay, sand, and salt. In certain embodiments, a subterranean formation 110 can also include one or more reservoirs in which one or more resources (e.g., oil, gas, water, steam) can be located. One or more of a number of field operations (e.g., drilling, setting casing, extracting downhole resources) can be performed to reach an objective of a user with respect to the subterranean formation 110.

The wellbore 120 can have one or more of a number of segments, where each segment can have one or more of a number of dimensions. Examples of such dimensions can include, but are not limited to, size (e.g., diameter) of the wellbore 120, a curvature of the wellbore 120, a total vertical depth of the wellbore 120, a measured depth of the wellbore 120, and a horizontal displacement of the wellbore 120. The field equipment 130 can be used to create and/or develop (e.g., insert casing pipe, extract downhole materials) the wellbore 120. The field equipment 130 can be positioned and/or assembled at the surface 102. The field equipment 130 can include, but is not limited to, an optional control unit 109 (including an optional hydraulic operating control line 121, as explained below), a derrick, a tool pusher, a clamp, a tong, drill pipe, a drill bit, example isolator subs, tubing pipe, a power source, and casing pipe.

The field equipment 130 can also include one or more devices that measure and/or control various aspects (e.g., direction of wellbore 120, pressure, temperature) of a field operation associated with the wellbore 120. For example, the field equipment 130 can include a wireline tool that is run through the wellbore 120 to provide detailed information (e.g., curvature, azimuth, inclination) throughout the wellbore 120. Such information can be used for one or more of a number of purposes. For example, such information can dictate the size (e.g., outer diameter) of casing pipe to be inserted at a certain depth in the wellbore 120.

Inserted into and disposed within the wellbore are a number of casing pipe 125 that are coupled to each other to form the casing string 124. In this case, each end of a casing pipe 125 has mating threads disposed thereon, allowing a casing pipe 125 to be mechanically coupled to an adjacent casing pipe 125 in an end-to-end configuration. The casing pipes 125 of the casing string 124 can be mechanically coupled to each other directly or using a coupling device, such as a coupling sleeve. The casing string 124 is not disposed in the entire wellbore 120. Often, the casing string 124 is disposed from approximately the surface 102 to some other point in the wellbore 120. The open hole portion 127 of the wellbore 120 extends beyond the casing string 124 at the distal end of the wellbore 120.

Each casing pipe 125 of the casing string 124 can have a length and a width (e.g., outer diameter). The length of a casing pipe 125 can vary. For example, a common length of a casing pipe 125 is approximately 40 feet. The length of a casing pipe 125 can be longer (e.g., 60 feet) or shorter (e.g., 10 feet) than 40 feet. The width of a casing pipe 125 can also vary and can depend on the cross-sectional shape of the casing pipe 125. For example, when the cross-sectional shape of the casing pipe 125 is circular, the width can refer to an outer diameter, an inner diameter, or some other form of measurement of the casing pipe 125. Examples of a width in terms of an outer diameter can include, but are not limited to, 7 inches, 7⅝ inches, 8⅝ inches, 10¾ inches, 13⅜ inches, and 14 inches.

The size (e.g., width, length) of the casing string 124 is determined based on the information gathered using field equipment 130 with respect to the wellbore 120. The walls of the casing string 124 have an inner surface that forms a cavity 123 that traverses the length of the casing string 124. Each casing pipe 125 can be made of one or more of a number of suitable materials, including but not limited to stainless steel. In certain example embodiments, the casing pipes 125 are made of one or more of a number of electrically conductive materials. A cavity 123 can be formed by the walls of the casing string 124.

The casing check valve 250 can be considered a part of, or separate from, the casing string 124. In such a case, one or more example casing check valves 250 can be part of, or disposed within, the casing string 124. A casing check valve 250 can be placed at any location along the casing string 124. In any case, the top end of the casing check valve 250 can couple to a casing pipe 125. In some cases, as shown in FIG. 8 below, if the casing check valve 250 is not placed at the end of the casing string 124, the bottom end of the casing check valve 250 can couple to another casing pipe 125. In some cases, the portion of the wellbore 120 above the casing check valve 250 (between the casing check valve and the surface 102) can be called the cased section (or cased hole section) of the wellbore 120, and the portion of the wellbore 120 below the casing check valve 250 can be called the open end section of the wellbore 120. Further details of the casing check valve 250 are provided below with respect to FIGS. 2-8.

A number of tubing pipes 115 that are coupled to each other and inserted inside the cavity 123 form the tubing string 114. The collection of tubing pipes 115 can be called a tubing string 114. The tubing pipes 115 of the tubing string 114 are mechanically coupled to each other end-to-end, usually with mating threads. The tubing pipes 115 of the tubing string 114 can be mechanically coupled to each other directly or using a coupling device, such as a coupling sleeve or an isolator sub (both not shown). Each tubing pipe 115 of the tubing string 114 can have a length and a width (e.g., outer diameter). The length of a tubing pipe 115 can vary. For example, a common length of a tubing pipe 115 is approximately 30 feet. The length of a tubing pipe 115 can be longer (e.g., 40 feet) or shorter (e.g., 10 feet) than 30 feet. Also, the length of a tubing pipe 115 can be the same as, or different than, the length of an adjacent casing pipe 125.

The width of a tubing pipe 115 can also vary and can depend on one or more of a number of factors, including but not limited to the target depth of the wellbore 120, the total length of the wellbore 120, the inner diameter of the adjacent casing pipe 125, and the curvature of the wellbore 120. The width of a tubing pipe 115 can refer to an outer diameter, an inner diameter, or some other form of measurement of the tubing pipe 115. Examples of a width in terms of an outer diameter for a tubing pipe 115 can include, but are not limited to, 7 inches, 5 inches, and 4 inches.

In some cases, the outer diameter of the tubing pipe 115 can be such that a gap exists between the tubing pipe 115 and an adjacent casing pipe 125. The walls of the tubing pipe 115 have an inner surface that forms a cavity that traverses the length of the tubing pipe 115. The tubing pipe 115 can be made of one or more of a number of suitable materials, including but not limited to steel.

At the distal end of the tubing string 114 within the wellbore 120 is a bottom hole assembly (sometimes referred to herein as a “BHA”) 101. The BHA 101 can include a drill bit 108 at the far distal end. The drill bit 108 is used to extend the open hole portion 127 of the wellbore 120 in the formation 110 by cutting into the formation 110. The BHA 101 can also include one or more other components, including but not limited to an operating tool 107, one or more tubing pipes 115, a measurement-while-drilling tool, and a wrench flat. During a field operation that involves drilling (extending the open hole portion 127 of the wellbore 120), the tubing string 114, including the BHA 101, can be rotated by other field equipment 130.

In certain example embodiments, the operating tool 107 is included in the BHA 101. In such a case, the operating tool 107 can be considered a part of, or separate from, the tubing string 114. In some cases, the operating tool 107 is positioned away from the BHA 101, closer to the surface 102. In such a case, the operating tool 107 can be considered part of the tubing string 114. One or more example operating tools 107 can be part of, or disposed within, the tubing string 114. An operating tool 107 can be placed at any location along the tubing string 114. In any case, the top end of the operating tool 107 can couple to a tubing pipe 115. In addition, the bottom end of the operating tool 107 can couple to another tubing pipe 115 or some portion of the BHA 101. Further details of the operating tool 107 are provided below with respect to FIG. 2.

The optional control unit 109 can include one or more components that allow a user to control one or more components of the casing check valve 250 (e.g., a housing coupling feature of the actuating sleeve) and/or one or more components (e.g., a complementary coupling feature of an operating tool) that interact with the casing check valve 250 from the surface 102. Examples of such components of the control unit 109 can include, but are not limited to, a compressor, one or more valves, a pump, piping, and a computer. The hydraulic operating control line 121 can be disposed between the casing string 124 and the wall 140 of the wellbore 120 and/or within the casing string 124.

FIG. 1 shows a field operation that involves drilling. Those of ordinary skill in the art will appreciate that other field operations can be conducted in the setting of FIG. 1. For example, a field operation can be a wireline or similar type of logging operation. In such a case, one or more of the components of FIG. 1 can be altered to account for the field operation. For example, a wireline 114 (as an example) can replace the tubing string, and a wireline tool 101 (or, more generally, a logging tool 101) can replace the BHA. In such a case, an operating tool 107 can be part of the wireline 114 and allow the wireline tool 101 to pass beyond the casing check valve 250 and take measurements in the open hole portion 127 of the wellbore 120 by opening the flapper assembly using the distal extension of the actuating sleeve, all as described below. In light of this flexibility between field operations, the tubing string 114 can more generally be called an operational string 114.

FIG. 2 shows a cross-sectional side view of a subsystem 201 that includes a casing check valve 250 in a normal position in accordance with certain example embodiments. In one or more embodiments, one or more of the features shown in FIG. 2 may be omitted, added, repeated, and/or substituted. Accordingly, embodiments of a casing check valve should not be considered limited to the specific arrangements of components shown in FIG. 2. For example, while the flapper seat 239 is shown and described below as being part of the bottom portion 234 of the housing body 256, the flapper seat 239 could be part of the middle portion 233 of the housing body 256.

Referring to FIGS. 1 and 2, the casing check valve 250 can have a housing 298 and an actuating sleeve 260. In certain example embodiments, the housing 298 includes a housing body 256. The housing body 256 can have multiple portions. For example, as shown in FIG. 2, the housing body 256 can have a top portion 232 (also called a top end 232), a middle portion 233 (also called a middle section 233), and a bottom portion 234 (also called a bottom end 234). The various portions of the housing body 256 of the casing check valve 250 can be made from a single piece or multiple pieces. The housing body 256 can have a height 292 and a width 280. Each portion of the housing body 256 can have a common outer surface 251. A cavity 289 disposed inside of the housing body 256 can traverse the height 292 of the housing body 256. The cavity 289 can be the same as, or different than, the cavity 123 of the casing string 124.

The top end 232 of the housing body 256 of FIG. 2 can have an inner surface 252, a top surface 254, the outer surface 251, and a bottom surface 278. In certain example embodiments, the housing body 256 can also include coupling features 299 disposed on and/or between the inner surface 252 and/or the top surface 254. In such a case, the coupling features 299 (e.g., mating threads) can be used to couple to an adjacent casing pipe 125. The inner surface 252 can form the cavity 289 that traverses the height 275 of the top end 232. The inner surface 252 of the top portion 232, when viewed cross-sectionally from above, can have one or more of a number of shapes. Examples of such shapes can include, but are not limited to, a circle, an oval, a square, and a hexagon.

In certain example embodiments, the cross-sectional shape formed by the inner surface 252 of the top end 232 can be substantially the same as the cross-sectional shape formed by the inner surface of an adjacent casing pipe 125. Similarly, the size (e.g., perimeter) of the cross-sectional area formed by the inner surface 252 of the top portion 232 can be substantially the same as the size of the cross-sectional area formed by the inner surface of a casing pipe 125. In this case, the cross-sectional shape formed by the inner surface 252 is a circle having a diameter 242. Likewise, the size and shape of the cross-section formed by the outer surface 251 of the top end 232 can be substantially the same as the size and shape of the cross-section formed by the outer surface of a casing pipe 125.

The bottom end 234 of the housing body 256 of FIG. 2 can have an inner surface 287, a top surface (in this case, designated by the flapper seat 239), the outer surface 251, a bottom surface 255, a flapper assembly 286, and a recessed area 280 disposed within a portion of the inner surface 287 adjacent to the flapper assembly 286. The inner surface 287 can form the cavity 289 that traverses the height 235 of the bottom end 234. The inner surface 287 of the bottom end 234, when viewed cross-sectionally from above, can have one or more of a number of shapes. Examples of such shapes can include, but are not limited to, a circle, an oval, a square, and a hexagon. The cross-sectional shape formed by the inner surface 287 of the bottom end 234 can be substantially the same as the cross-sectional shape formed by the inner surface 252 of the top end 232. Thus, in this case, the cross-sectional shape formed by the inner surface 287 can be a circle.

In certain example embodiments, the cross-sectional shape formed by the inner surface 287 of the bottom end 234 can be substantially the same as the cross-sectional shape formed by the inner surface of a casing pipe 125. Similarly, as shown in FIG. 8 below, the size (e.g., perimeter) of the cross-sectional area formed by the inner surface 287 of the bottom end 234 can be substantially the same as the size of the cross-sectional area formed by the inner surface 252 of the top end 232 and/or the inner surface of a casing pipe 125.

Alternatively, as shown in FIG. 2, the size of the cross-sectional area formed by the inner surface 287 of the bottom end 234 can be different than the size of the cross-sectional area formed by the inner surface 252 of the top end 232 and/or the inner surface of a casing pipe 125. In this example, the inner surface 287 of the bottom end 234 has a diameter 243 that is larger than the diameter 242 of the inner surface 252 of the top end 232 and the inner surface of the casing pipe 125. Similarly, the size and shape of the cross-section formed by the outer surface 251 of the bottom end 234 can be substantially the same as, or different than, the size and shape of the cross-section formed by the outer surface 251 of the top end 232 and/or the outer surface of a casing pipe 125.

As described below with respect to FIG. 8, one or more optional coupling features (e.g., mating threads) can be disposed on or between the inner surface 287 and the bottom surface 255 of the bottom end 234, where these coupling features can be used to mechanically couple the casing check valve 250 to an adjacent casing pipe 125 in the casing string 124. In the example shown in FIG. 2, there are no coupling features disposed on the bottom portion 234 because the casing check valve is disposed at the end of the casing string 124.

In certain example embodiments, the flapper seat 239 is one or more protrusions that extend inward by a distance 270 from the inner surface 287 of the bottom end 234, into the cavity 289. The purpose of the flapper seat 239 is to prevent the flapper 271 of the flapper assembly 286 (discussed below) from traveling beyond a certain point toward the middle section 233 of the housing body 256. The flapper seat 239 can be one or more discrete protrusions that extend inward from the inner surface 287 of the bottom end 234. Alternatively, the flapper seat 239 can be a single protrusion that is continuous around the inner surface 287 of the bottom end 234. The distance 285 within the cavity 289 defined by the flapper seat 239 can be less than the length of the flapper 271. In addition, the distance 285 can be at least as great as the inner diameter 242 of the casing pipe 125. The flapper seat 239 can have a thickness 284.

In certain example embodiments, the flapper assembly 286 includes a flapper 271 and a hinge 272 and is disposed, at least in part, along the inner surface 287 of the bottom portion 234. The hinge 272 can be disposed within or adjacent to the housing body 256. The hinge 272 can be used to move the flapper 271 between a closed position (e.g., when the flapper 271 abuts against the flapper seat 239) and an open position (e.g., when the flapper 271 is positioned in the recessed area 280 (discussed below). When in the closed position, the flapper 271 can create a seal against the flapper seat 239, preventing substantially any material (e.g., fluids, gases) from traveling within the cavity 289 between the bottom portion 234 and the middle portion 233. The flapper 271 can have a thickness 277.

The closed position of the flapper 271 can be the default position of the flapper 271. In other words, the hinge 272 can operate on a mechanical (e.g., a spring), hydraulic, or other basis to put the flapper 271 in the default (in this case, the closed) position. The force that the hinge 272 applies to the flapper 271 in the closed position can be overcome by a greater force, such as the force applied by the distal extension 264 of the actuating sleeve 260 (described below) on the flapper 271 when the actuating sleeve 260 is moved toward an actuated position. For example, as shown in FIG. 3, when the actuating sleeve 260 is moved toward the actuating sleeve, the distal extension 264 forces the flapper 271 to move from the closed position to the open position.

The recessed area 280 has a height 294 and a width 245 that is at least as great as the height and the width of the flapper 271. In this way, when the flapper 271 is in the open position, the flapper fits entirely within the recessed area 280 and does not protrude beyond the inner wall 287 toward the cavity 289. As a result, the housing body 256 has a thickness 231 that is less than the thickness 246 of the rest of the housing body 256 in the bottom portion 234. The recessed area 280 can be disposed along a portion (as shown in FIG. 2) or all of the perimeter of the inner surface of the bottom portion 234. The recessed area 280 can be defined, at least in part, by the inner surface 290 and the bottom surface 291. The remainder of the bottom portion 234 adjacent to (below) the recessed area 280 can have a height 276.

In certain example embodiments, the middle section 233 of the housing body 256 is disposed between the top end 232 and the bottom end 234. The middle section 233 can include the outer surface 251, the inner surface 287, and at least one actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 254, actuating sleeve coupling feature 257). The inner surface 287 can form the cavity 289 that traverses the height 261 of the middle portion 233. The inner surface 287 of the middle portion 233, when viewed cross-sectionally from above, can have one or more of a number of shapes. Examples of such shapes can include, but are not limited to, a circle, an oval, a square, and a hexagon. The cross-sectional shape formed by the inner surface 287 of the middle portion 233 can be substantially the same as the cross-sectional shape formed by at least a portion of the inner surface 287 of the bottom end 232. Thus, in this case, the cross-sectional shape formed by the inner surface 287 can be a circle.

Similarly, as shown in FIG. 8 below, the size (e.g., perimeter) of the cross-sectional area formed by the inner surface 287 of the middle portion 233 can be substantially the same as the size of the cross-sectional area formed by the inner surface 287 of at least a portion of the bottom end 234. In addition, the size and shape of the cross-section formed by the outer surface 251 of the middle portion 233 can be substantially the same as, or different than, the size and shape of the cross-section formed by the outer surface 287 of the bottom end 234 and/or the outer surface of a casing pipe 125.

In certain example embodiments, an actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 254, actuating sleeve coupling feature 257) can be disposed on the inner surface 287 of the middle portion 233 of the housing body 256. Each actuating sleeve coupling feature of the housing body 256 can have a shape, size, and features that allow it to become removably coupled to a housing coupling feature 263 of the actuating sleeve 260, as described below. For example, as shown in FIG. 2, the actuating sleeve coupling feature 254 and the actuating sleeve coupling feature 257 each form a recess into the housing body 256 from the inner surface 287. Specifically, the actuating sleeve coupling feature 254 and the actuating sleeve coupling feature 257 each have a back surface 237 that is adjacent to angled side surface 236 on one side and angled side surface 238 on the other side.

Angled side surface 236 and angled side surface 238 end at the inner surface 287 of the middle portion 233. Further, the angle between the angled side surface 236 and the back surface 237, as well as the angle between the angled side surface 238 and the back surface 237, can be obtuse to allow for movement of the housing coupling feature 263 from one actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 254) to another actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 257) without decoupling the operating tool coupling feature 266 of the actuating sleeve 260 and the complementary coupling feature 106 of the operating tool 107, as described below.

In certain example embodiments, there can be one or more stops disposed on an inner surface of the housing body 256. The stops can be used to limit the travel of the actuating sleeve 260 within the cavity 289. For example, the bottom surface 278 of the top portion 232 can serve as a stop. In such a case, the bottom surface 278 of the top portion 232 can act as a stop to position the actuating sleeve 260 in a normal position. As another example, the flapper seat 239 can serve as a stop. In such a case, the flapper seat 239 can act as a stop to position the actuating sleeve 260 in an actuated position.

The positioning of the stops can coincide with the positioning of the actuating sleeve coupling features. For example, the actuating sleeve coupling feature 257 can be located a distance 295 from the actuating sleeve coupling feature 254, which can coincide with when the top surface 268 of the actuating sleeve 260 abuts against the bottom surface 278 of the housing body 256 and when the bottom surface 258 of the actuating sleeve 260 abuts against the flapper seat 239 of the housing 298, respectively.

The top portion 232 and/or the bottom portion 234 of the housing body 256 can be merged with (e.g., form a single piece with) the middle portion 233. Alternatively, one or more of the top portion 232, the middle portion 233, and the bottom portion 234 of the housing body 256 can be a separate piece that is coupled to one or more other portions of the housing body 256 using one or more coupling features. For example, the middle portion 233 can be coupled to the top portion 232 and the bottom portion 234 using a coupling feature (e.g., mating threads). The middle portion 233 can be disposed at any point along the height 292 of the housing body 256 relative to the top portion 232 and the bottom portion 234.

In certain example embodiments, the actuating sleeve 260 is movably disposed within the cavity 289 formed by the housing body 256. For example, as shown in FIG. 2, at least a portion of the actuating sleeve 260 is disposed adjacent to the middle portion 233 of the housing body 256. The actuating sleeve 260 can include one or more of a number of components. For example, as shown in FIG. 2, the actuating sleeve 260 can include an actuating sleeve body 240, at least one housing coupling feature 263, at least one operating tool coupling feature 266, and a distal extension 260. The various portions of the actuating sleeve 260 can be made from a single piece or multiple pieces.

In certain example embodiments, the actuating sleeve body 240 has an inner surface 267, a top surface 268, an outer surface 204, and a bottom surface 258. The actuating sleeve body 240 can have a height 249, a width 244 (defined by the outer surface 204), and a width 242 of the cavity 222 (defined by the inner surface 267). A cavity 222 disposed inside of the actuating sleeve body 240 can traverse the height 249 of the actuating sleeve body 240. The cavity 222 can be a subset of the cavity 289 of the housing body 256. The cavity 222 can also be disposed within the distal extension 260 of the actuating sleeve 260. The inner surface 267 of the actuating sleeve body 240, when viewed cross-sectionally from above, can have one or more of a number of shapes. Examples of such shapes can include, but are not limited to, a circle, an oval, a square, and a hexagon.

In certain example embodiments, the cross-sectional shape formed by the inner surface 267 of the actuating sleeve body 240 can be substantially the same as the cross-sectional shape formed by the inner surface 287 of the middle portion 233 of the housing body 256. Similarly, the size (e.g., perimeter, diameter 244) of the cross-sectional area formed by the outer surface 204 of the actuating sleeve body 240 can be less than the size (e.g., perimeter, diameter 243) of the cross-sectional area formed by the inner surface 287 of the middle portion 233 of the housing body 256. In such a case, the actuating sleeve 260 can move (e.g., slide) within the cavity 289 formed by the middle portion 233 of the housing body 256.

Each housing coupling feature 263 of the actuating sleeve 260 is disposed on the outer surface 204 of the actuating sleeve body 240. The housing coupling feature 263 can extend outward from the outer surface 204. In certain example embodiments, the housing coupling feature 263 is retractable (e.g., can move inward and outward, perpendicular with respect to the outer surface 204). In such a case, the normal position of the housing coupling feature 263 can be outward, as shown in FIG. 2, where the housing coupling features 263 are disposed within the recess formed by the actuating sleeve coupling feature 257. The normal position of the housing coupling features 263 can be maintained by one or more components, including but not limited to one or more springs mounted within the actuating sleeve body 240. Alternatively, the housing coupling features 263 can be made of a semi-flexible material that reverts to its normal state when insufficient forces are applied to move it to a retracted state.

As the actuating sleeve 240 moves from a normal position (in this case, corresponding to when the housing coupling features 263 are coupled to (e.g., disposed within) the actuating sleeve coupling feature 257) to an actuated position (in this case, corresponding to when the housing coupling features 263 are coupled to (e.g., disposed within) the actuating sleeve coupling feature 254), the housing coupling features 263 are pressed inward by the inner surface 287 of the middle portion 233 of the housing body 256. When the actuating sleeve 240 is in the normal position or the actuated position, the housing coupling features 263 are extended (in their normal position). In certain example embodiments, each housing coupling feature 263 is a collet.

As discussed above, the housing coupling features 263 can have one or more features that complement the features of the actuating sleeve coupling features of the housing body 256. In this example, each housing coupling feature 263 can have a front surface 228 that is adjacent to angled side surface 227 on one side and angled side surface 229 on the other side. The angle between the angled side surface 227 and the front surface 228, as well as the angle between the angled side surface 229 and the front surface 228, can be obtuse to allow for retraction of the housing coupling feature 263, allowing the actuating sleeve 260 to move from one actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 254) to another actuating sleeve coupling feature (e.g., actuating sleeve coupling feature 257). Again, the retractability of the housing coupling features 263 help allow for movement of the actuating sleeve 260 without decoupling the operating tool coupling feature 266 of the actuating sleeve 260 and the complementary coupling feature 106 of the operating tool 107, as described below.

In certain example embodiments, one or more operating tool coupling features (e.g., operating tool coupling feature 266) can be disposed on the inner surface 267 of the actuating sleeve body 240. Each operating tool coupling feature 266 of the actuating sleeve body 240 can have a shape, size, and features that allow it to become removably coupled to a complementary coupling feature 106 of the operating tool 107, as described below. For example, as shown in FIG. 2, the operating tool coupling feature 266 can form a recess into the actuating sleeve body 240 from the inner surface 267. Specifically, the operating tool coupling feature 266 can have a back surface 282 that is adjacent to angled side surface 281 on one side and angled side surface 283 on the other side.

Angled side surface 281 and angled side surface 283 end at the inner surface 267 of the actuator sleeve body 240. Further, the angle between the angled side surface 281 and the back surface 282, as well as the angle between the angled side surface 283 and the back surface 282, can be obtuse to allow for movement of the complementary coupling feature 106 when the actuating sleeve 260 has reached its normal position or its actuated position relative to the housing body 256.

In certain example embodiments, the distal extension 264 of the actuating sleeve 260 extends from a distal end (in this case, from bottom surface 258) of the actuating sleeve body 240. The distal extension 264 can be defined by the inner surface 267, a bottom surface 269, and an outer surface 261. The thickness of the distal extension 264 can be defined by the diameter 279 of the outer surface 261 less the diameter 242 of the inner surface 267. Alternatively, the thickness of the distal extension 264 can be defined by the diameter 244 of the outer surface 204 of the actuating sleeve body 240 less the length 259 of the bottom surface 269 of the actuating sleeve body 240. The diameter 279 of the outer surface 261 of the distal extension 264 can be less than the distance 285 within the cavity 289 defined by the flapper seat 239.

As shown in FIG. 2, when the actuating sleeve 260 is in the normal position, the distal extension 264 is positioned within the cavity 289 defined by the middle portion 233 of the housing body 256. In such a case, the distal extension 264 does not contact the flapper 271 of the flapper assembly 286, where the flapper 271 is in the closed position by abutting against the flapper seat 239. As the actuating sleeve 260 moves from the normal position to the actuated position, as shown in FIG. 3 below, the distal extension 264 contacts the flapper 271 and applies enough downward force to the flapper 271 to overcome the opposing force of the hinge 272, forcing the flapper into the open position.

In certain example embodiments, the operating tool 107 disposed within the tubing string 114 (and, more specifically, to a tubing pipe 115) has one or more complementary coupling features 106. Each complementary coupling feature 106 of the operating tool 107 is disposed on the outer surface of the operating tool 107. The complementary coupling feature 106 can extend outward from the outer surface of the operating tool 107. In certain example embodiments, the complementary coupling feature 106 is retractable (e.g., can move inward and outward, perpendicular with respect to the outer surface). In such a case, the normal position of the complementary coupling feature 106 can be outward, as shown in FIG. 2, where the complementary coupling features 106 are disposed within the recess formed by the operating tool coupling feature 266. The normal position of the complementary coupling features 106 can be maintained by one or more components, including but not limited to one or more springs mounted within the operating tool 107. Alternatively, the complementary coupling features 106 can be made of a semi-flexible material that reverts to its normal state when insufficient forces are applied to move it to a retracted state.

As yet another alternative, the complementary coupling features 106 can operate using hydraulic control. In such a case, the control unit 109, using the hydraulic operating control line 121, can apply a hydraulic pressure to a hydraulic material to maintain the complementary coupling features 106 in an extended position and remove the hydraulic pressure to allow the complementary coupling features 106 to move to a retracted position. In certain example embodiments, the hydraulic material can be a liquid (fluid), a gas (in which case, the hydraulic material can also be called a pneumatic material), or have any other suitable state. A non-limiting example of a hydraulic material is oil.

The movement of the operating tool 107 (and, thus, the tubing string 114) moves vertically within the cavity 222 of the actuating sleeve body 240, the actuating sleeve 240 moves between the normal position (in this case, corresponding to when the housing coupling features 263 are coupled to (e.g., disposed within) the actuating sleeve coupling feature 257) and the actuated position (in this case, corresponding to when the housing coupling features 263 are coupled to (e.g., disposed within) the actuating sleeve coupling feature 254). Once the actuating sleeve 240 reaches either of these positions relative to the housing body 256, as the operating tool 107 continues to move in the same direction, the force applied to the tubing string 114 overcomes the coupling force (either by the configuration of these coupling features or by some other factor, such as hydraulic control) between the complementary coupling features 106 of the operating tool 107 and the operating tool coupling features 266 of the actuating sleeve 260. In certain example embodiments, the complementary coupling features 106 of the operating tool 107 is called a dog.

As discussed above, the complementary coupling features 106 can have one or more features that complement the features of the operating tool coupling features 266 of the actuating sleeve 260. In this example, each complementary coupling feature 106 can have a front surface 113 that is adjacent to angled side surface 112 on one side and angled side surface 116 on the other side. There can also be a side surface 111 that extends from the outer surface of the operating tool 107 and joins with the angled side 112, as well as another side surface 117 that extends from the outer surface of the operating tool 107 and joins with the angled side 116. The angle between the angled side surface 112 and the front surface 113, as well as the angle between the angled side surface 116 and the front surface 113, can be obtuse to allow for retraction of the complementary coupling feature 106, allowing the operating tool 107 (and, thus, the tubing string 114) to move beyond the casing check valve 250.

For example, if a tripping operation of the tubing string 114 were occurring, where the tubing string 114 is being drawn to the surface 102, when the housing coupling feature 263 of the actuating sleeve 260 is coupled to the actuating sleeve coupling feature 257 of the housing body 256, putting the actuating sleeve 260 in the normal position, then the top surface 268 of the actuating sleeve 260 abuts against the bottom surface 278 of the housing body 256. When this occurs, the actuating sleeve 260 cannot move further toward the surface 102. In other words, the furthest length of proximal travel for the actuating sleeve 260 within the cavity 289 formed by the middle portion 233 of the housing body 256 can be when the actuating sleeve 260 is in the normal position. As a result, this holding force by the housing body 256 on the actuating sleeve 260, as the tubing string 114 moves toward the surface 102, is strong enough to overcome the force that couples the operating tool coupling features 266 of the actuating sleeve 260 with the complementary coupling features 106 of the operating tool 107. Consequently, the tubing string 114, including the operating tool 107, can be lifted up through the cavity 123 of the casing string 124, away from the casing check valve 250.

FIGS. 3 and 4 show a subsystem cross-sectional side view of the casing check valve of FIG. 2 in an open position in accordance with certain example embodiments. In one or more embodiments, one or more of the features shown in FIGS. 3 and 4 may be omitted, added, repeated, and/or substituted. Accordingly, embodiments of a casing check valve should not be considered limited to the specific arrangements of components shown in FIGS. 3 and 4.

The components in the subsystem 301 of FIG. 3 and the subsystem 401 of FIG. 4 are substantially similar to the corresponding components in the subsystem 201 of FIG. 2, except as described below. Referring to FIGS. 1-4, the casing check valve 350 (and, more specifically, the actuating sleeve 260) of the subsystem 301 of FIG. 3 and the casing check valve 450 of the subsystem 401 of FIG. 4 are shown in the actuated position. In FIG. 3, the tubing string 114 is inserted further into the wellbore 120 toward the open hole portion 127 to extend the wellbore 120. In the subsystem 301 of FIG. 3, the complementary coupling features 106 of the operating tool 107 are engaged with (coupled to) the operating tool coupling features 266 of the actuating sleeve 260.

As the tubing string 114 (and, more specifically, the operating tool 107) is moved downward in the wellbore 120, the actuating sleeve 260 moves with respect to the housing body 256 from the normal position (as shown in FIG. 2) to the actuated position (as shown in FIG. 3). Specifically, in the actuated position of FIG. 3, the housing coupling feature 263 of the actuator sleeve 260 are coupled to (e.g., disposed within) the actuating sleeve coupling feature 254 of the housing body 256.

As described above, when the actuating sleeve 260 is in the normal position, the distal extension 264 is positioned within the cavity 289 defined by the middle portion 233 of the housing body 256. In such a case, the distal extension 264 does not contact the flapper 271 of the flapper assembly 286, where the flapper 271 is in the closed position by abutting against the flapper seat 239. As the actuating sleeve 260 moves from the normal position (as shown in FIG. 2, putting the casing check valve 250 in the closed position) to the actuated position, as shown in FIG. 3, the distal extension 264 contacts the flapper 271 and applies enough downward force to the flapper 271 to overcome the opposing force of the hinge 272, forcing the flapper into the open position. In other words, the flapper 271 is forced into and held within the recessed area 280 when the actuating sleeve 260 is in the actuated position with respect to the housing body 256. When the actuating sleeve 260 is in the actuated position, the casing check valve 350 is in the open position.

In FIG. 4, the tubing string 114 is inserted even further (relative to FIG. 3) into the wellbore 120 toward the open hole portion 127 to extend the wellbore 120. In the subsystem 401 of FIG. 4, the complementary coupling features 106 of the operating tool 107 become engaged from (are decoupled from) the operating tool coupling features 266 of the actuating sleeve 260. Specifically, when the housing coupling feature 263 of the actuating sleeve 260 is coupled to the actuating sleeve coupling feature 254 of the housing body 256, putting the actuating sleeve 260 in the actuated position, then the bottom surface 258 of the actuating sleeve 260 abuts against the flapper seat 239 of the housing 298.

When this occurs, the actuating sleeve 260 cannot move further toward the open hole portion 127 of the wellbore 120. In other words, the furthest length of distal travel for the actuating sleeve 260 within the cavity 289 formed by the middle portion 233 of the housing body 256 can be when the actuating sleeve 260 is in the actuated position. As a result, this holding force by the housing body 256 on the actuating sleeve 260, as the tubing string 114 moves toward the open hole portion 127 of the wellbore 120, is strong enough to overcome the force that couples the operating tool coupling features 266 of the actuating sleeve 260 with the complementary coupling features 106 of the operating tool 107. Consequently, the tubing string 114, including the operating tool 107, can be inserted through the cavity 123 of the casing string 124, away from the casing check valve 250.

FIGS. 5-7 show a cross-sectional side view of another casing check valve 550 in a closed position in accordance with certain example embodiments. In one or more embodiments, one or more of the features shown in FIGS. 5-7 may be omitted, added, repeated, and/or substituted. Accordingly, embodiments of a casing check valve should not be considered limited to the specific arrangements of components shown in FIGS. 5-7.

The components in the subsystem 501 of FIG. 5 are substantially similar to the corresponding components in the subsystem 201 of FIG. 2, except as described below. Referring to FIGS. 1-7, the casing check valve 550 of the subsystem 501 of FIG. 5 is shown in the closed position as a result of the actuating sleeve 560 being in the normal position with respect to the housing body 556. With the casing check valve 550 of FIG. 5, the housing coupling feature 563 of the actuating sleeve 560, as well as the actuating sleeve coupling feature 557 of the housing body 556 have different configurations. Specifically, in this case, the housing coupling feature 563 and the actuating sleeve coupling feature 557 are mating threads that complement each other.

Because of the length of the mating threads disposed on the inner surface 587 of the housing body 556 in FIG. 5, there are not multiple actuating sleeve coupling features, as with the casing check valve 250 of FIG. 2. Alternatively, there can be multiple sets of mating threads (where each set of mating threads represents a actuating sleeve coupling feature) disposed on the inner surface 587 of the housing body 556. The actuating sleeve 560 can move between the normal position (putting the casing check valve 550 in the closed position) and the actuated position (putting the casing check valve 550 in the open position) by rotating relative to the housing body 556.

This rotation of the actuating sleeve 560 can be caused by the rotation of the tubing string 114 (which includes the operating tool 107). During a field operation, the tubing string 114 is rotated in one direction (e.g., clockwise) when tubing pipes 115 are being added to the tubing string 114 (as during drilling), and the tubing string 114 is rotated in the opposite direction (e.g., counter-clockwise) when tubing pipes 115 are being removed from the tubing string 114 (as during a tripping run). When the complementary coupling features 106 of the operating tool 107 are engaged with (coupled to) the operating tool coupling features 566 of the actuating sleeve 560, the actuating sleeve 560 rotates along with the operating tool 107.

As the tubing string 114 is removed from the wellbore, pulling the operating tool 107 upward, the rotation of the operating tool 107 moves the actuating sleeve 560 to the normal position, putting the casing check valve 550 in the closed position. When the top surface 568 of the actuating sleeve 560 abuts against the bottom surface 578 of the housing body 556, the actuating sleeve 560 cannot move further toward the surface 102. In other words, the furthest length of proximal travel for the actuating sleeve 560 within the cavity 589 formed by the middle portion 533 of the housing body 556 can be when the actuating sleeve 560 is in the normal position. As a result, this holding force by the housing body 556 on the actuating sleeve 560, as the tubing string 114 moves toward the surface 102, is strong enough to overcome the force that couples the operating tool coupling features 566 of the actuating sleeve 560 with the complementary coupling features 106 of the operating tool 107. Consequently, the tubing string 114, including the operating tool 107, can be lifted up through the cavity 123 of the casing string 124, away from the casing check valve 550.

In the subsystem 601 of FIG. 6, the tubing string 114 is inserted further into the wellbore 120 toward the open hole portion 127 to extend the wellbore 120. Relative to the subsystem 501 of FIG. 5, the complementary coupling features 106 of the operating tool 107 continue to be engaged with (coupled to) the operating tool coupling features 566 of the actuating sleeve 560, but the operating tool 107 (along with the rest of the tubing string 114) is rotating in the opposite direction. As the tubing string 114 (and, more specifically, the operating tool 107) is moved downward in the wellbore 120, the actuating sleeve 560 rotates downward with respect to the housing body 556 from the normal position (as shown in FIG. 5) to the actuated position (as shown in FIG. 6).

As described above, when the actuating sleeve 560 is in the normal position, the distal extension 564 is positioned within the cavity 589 defined by the middle portion 533 of the housing body 556. In such a case, the distal extension 564 does not contact the flapper 571 of the flapper assembly 586, where the flapper 571 is in the closed position by abutting against the flapper seat 539. As the actuating sleeve 560 moves from the normal position (as shown in FIG. 5, putting the casing check valve 550 in the closed position) to the actuated position, as shown in FIG. 6, the distal extension 564 contacts the flapper 571 and applies enough downward force to the flapper 571 to overcome the opposing force of the hinge 572, forcing the flapper 571 into the open position. In other words, the flapper 571 is forced into and held within the recessed area 580 when the actuating sleeve 560 is in the actuated position with respect to the housing body 556. When the actuating sleeve 560 is in the actuated position, the casing check valve 650 is in the open position.

As the actuating sleeve 560 continues to rotate downward relative to the housing body 556 using the housing coupling feature 563 and the actuating sleeve coupling feature 557, the bottom surface 558 of the actuating sleeve 560 eventually abuts against the flapper seat 539 of the housing body 556. When this occurs, as shown in FIG. 6, the actuating sleeve 560 cannot move further toward the open hole portion 127 of the wellbore 120. In other words, the furthest length of distal travel for the actuating sleeve 560 within the cavity 589 formed by the middle portion 533 of the housing body 556 can be when the actuating sleeve 560 is in the actuated position, putting the casing check valve 650 in the open position.

If the tubing string 114 continues to rotate, moving the operating tool 107 further into the open hole portion 127 of the wellbore 120, the holding force by the housing body 556 on the actuating sleeve 560 (e.g., where the bottom surface 558 of the actuating sleeve 560 abuts against the flapper seat 539 of the housing body 556) is strong enough to overcome the force that couples the operating tool coupling features 566 of the actuating sleeve 560 with the complementary coupling features 106 of the operating tool 107. Consequently, as shown in FIG. 7, the tubing string 114, including the operating tool 107, can be inserted through the cavity 123 of the casing string 124, away from the casing check valve 750.

FIG. 8 shows a cross-sectional side view of a subsystem 801 that includes yet another casing check valve 850 in an open position in accordance with certain example embodiments. In one or more embodiments, one or more of the features shown in FIG. 8 may be omitted, added, repeated, and/or substituted. Accordingly, embodiments of a casing check valve should not be considered limited to the specific arrangements of components shown in FIG. 8.

The components in the subsystem 801 of FIG. 8 are substantially similar to the corresponding components in the subsystem 201 of FIG. 2, except as described below. Referring to FIGS. 1-8, the casing check valve 850 of FIG. 8 is not at the distal end of the casing string 124. Instead, in addition to the casing check valve 850 being coupled to a casing pipe 125 at the top portion 832 of the housing body 856, the casing check valve 850 is also coupled to another casing pipe 125 at the bottom portion 834 of the housing body 856.

The bottom portion 834 of the housing body 856 can be coupled to a casing pipe 125 using one or more of a number of coupling features 873 disposed on and/or between the bottom surface 855 and/or the inner surface 893. The coupling feature 899 can be the same as, or different than, the coupling feature 873 of the top portion 832 of the housing body 856. By having the casing check valve 850 disposed within, rather than at the distal end of, the casing string 124, the point at which the wellbore 120 is isolated by the casing check valve 850 can be controlled. In addition, multiple casing check valves can be disposed at various points along the casing string 125 to isolate multiple zones of the wellbore 120.

When the bottom portion 834 of the housing body 856 includes a coupling feature 873 to coupling the casing check valve 850 to a casing pipe 125, the thickness of the portion of the bottom portion 834 that is clear of the movement of the flapper assembly 886 can be increased compared to the thickness of the bottom portion 234 of the housing body 256 of the casing check valve 250 of FIG. 2. For example, the thickness of the portion of the bottom portion 834 that is clear of the movement of the flapper assembly 886 can be substantially the same as the thickness of the top portion 832 of the housing body 856, so that the inner surface 893 of the bottom portion 834 forms a diameter 242 that is substantially the same as the diameter 242 formed by the inner surface 252 of the top portion 832.

FIG. 9 is a flowchart presenting a method 900 for isolating a section of a wellbore using a casing check valve in accordance with certain example embodiments. While the various steps in this flowchart are presented and described sequentially, one of ordinary skill will appreciate that some or all of the steps may be executed in different orders, may be combined or omitted, and some or all of the steps may be executed in parallel. Further, in one or more of the example embodiments, one or more of the steps described below may be omitted, repeated, and/or performed in a different order. In addition, a person of ordinary skill in the art will appreciate that additional steps not shown in FIG. 9, may be included in performing this method. Accordingly, the specific arrangement of steps should not be construed as limiting the scope.

Referring now to FIGS. 1-9, the example method 900 begins at the START step and proceeds to step 902, where a coupling feature 106 of an operating tool 107 is received. In certain example embodiments, the operating tool 107 is part of a tubing string 114. The coupling feature 106 (also called a complementary coupling feature 106 above) can be coupled to an operating tool coupling feature 266 of an actuating sleeve 260 of a casing check valve 250. When this occurs, the actuating sleeve 260 is in some position (e.g., actuated position, normal position) relative to the housing body 256. The position of the actuating sleeve 260 corresponds to a state of the flapper assembly. Specifically, when the actuating sleeve 260 is in the normal position, the flapper assembly 286 is in a closed state, and when the actuating sleeve 260 is in the actuated position, the flapper assembly 286 is in an open state. When the flapper assembly 286 is in the closed state, the casing check valve is closed, and when the flapper assembly 286 is in the open state, the casing check valve is open.

In step 904, the actuating sleeve 260 is repositioned within a housing body 256 from a first position to a second position. In certain example embodiments, the actuating sleeve 260 is repositioned based on movement of the operating tool 107 in a direction (e.g., toward the surface 102, toward the open hole portion 127 of the wellbore 120). Repositioning the actuating sleeve 260 from the first position (e.g., the normal position) to the second position (e.g., the actuated position) changes a flapper assembly 286 from a first state (e.g., the closed state) to a second state (e.g., the open state).

In step 906, the coupling feature 106 of the operating tool 107 is released. The coupling feature 106 can be released by (decoupled from) the operating tool coupling feature 266 of the actuating sleeve 260. Releasing the coupling feature 106 can be based on continued movement of the operating tool 107 in the same direction that it was moving in step 904. The coupling feature 106 can be decoupled from the operating tool coupling feature 266 based on the mechanical forces (e.g., the bottom surface 258 of the actuating sleeve 260 abutting against the flapper seat 239 of the housing 298), hydraulic forces (e.g., operation of the control unit 109 using the hydraulic operating control line 121), or some other means. When the coupling feature 106 of the operating tool 107 is released, the coupling feature 106 can be retracted. When the coupling feature 106 of the operating tool 107 is released, the casing check valve 250 maintains its position until the operating tool 107 passes in the opposite direction, at which time the method 900 can be repeated. Once step 906 is completed, the process ends with the END step.

By performing the method 900 of FIG. 9, the casing check valve 250 can be used in one or more of a number of applications that requires isolating (e.g., in terms of pressure) portions of a wellbore 120. For example, embodiments of a casing check valve 250 described herein can isolate at least a distal portion of a casing string 124 and an open hole portion 127 of the wellbore 120 beyond the casing string 124. The casing check valve 250 can allow the tubing string 114 (including the BHA 101) to be tripped above the casing check valve 250 with the hydrostatic pressure of the mud column in the cavity 123 of the casing string 124 above the casing check valve 250 to be equal to, greater than (overbalanced), or less than (underbalanced) the open hole pressure below the casing check valve 250. In certain example embodiments, multiple casing check valves 250 can be part of and/or disposed along the length of the casing string 124 to provide redundancy and/or to isolate various sections of the wellbore 120 that are cased and/or open hole relative to each other.

The systems, methods, and apparatuses described herein allow for isolating one portion of the wellbore from the other portion of the wellbore. By isolating portions of the wellbore, the integrity of the wellbore (particularly the open hole portion of the wellbore) can be maintained. For example, example casing check valves can be utilized to prevent flow from the open hole portion of the wellbore up into the cased hole section of the wellbore when making a trip with the tubing string above the depth of the casing check valve in the wellbore. The example casing check valve described herein can allow the pressure below the casing check valve (the open hole portion of the wellbore) to be greater than the pressure above the casing check valve, enhancing tripping execution for underbalanced drilling operations. The example casing check valve can be closed mechanically (e.g., using the distal extension of the actuating sleeve) to prevent flow while tripping rather than requiring flow to activate the flapper assembly.

Example embodiments do not operate using hydraulic pressure, and so example casing check valves are not limited by hydrostatic pressure. Since the size of the flapper assembly of an example casing check valve can be at least as great as an inner diameter of adjacent casing pipe, the size of a casing check valve can be used with one of a number (within a range) of sizes of casing pipe. In addition, example embodiments help promote safety of personnel and equipment during a field operation, such as tripping, logging, and maintenance.

Although embodiments described herein are made with reference to example embodiments, it should be appreciated by those skilled in the art that various modifications are well within the scope and spirit of this disclosure. Those skilled in the art will appreciate that the example embodiments described herein are not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments using the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the example embodiments is not limited herein. 

What is claimed is:
 1. A casing check valve for providing isolation of an open hole section of a wellbore from a cased hole section of the wellbore, the casing check valve comprising: a housing comprising: a housing body forming a housing cavity that traverses therethrough, wherein the housing body comprises a top portion, a middle portion, and a bottom portion; at least one actuating sleeve coupling feature disposed on an inner surface of the middle portion of the housing body; a flapper assembly disposed along the inner surface of the bottom portion of the housing body; a flapper seat disposed on the inner surface of the bottom portion of the housing body adjacent to the flapper assembly; and a first casing pipe coupling feature disposed on the top portion of the housing body, wherein the first casing pipe coupling feature is configured to couple to a first casing pipe; and an actuating sleeve disposed within the housing cavity between an actuated position and a normal position, wherein the actuating sleeve is concentric with and adjacent to the housing, wherein the actuating sleeve comprises: an actuating sleeve body forming an actuating sleeve cavity; at least one housing coupling feature disposed on an outer surface of the actuating sleeve, wherein the at least one housing coupling feature is removably coupled to the at least one actuating sleeve coupling feature of the housing as the actuating sleeve moves between the actuated position and the normal position; at least one operating tool coupling feature configured to receive a complementary coupling feature of an operating tool disposed within the actuating sleeve cavity; and a distal extension that extends from a distal end of the actuating sleeve body, wherein the distal extension opens the flapper assembly when the actuating sleeve is in the actuated position, and wherein the distal extension allows the flapper to close when the actuating sleeve is in the normal position.
 2. The casing check valve of claim 1, further comprising: a second casing pipe coupling feature disposed on the bottom portion of the housing body, wherein the second casing pipe coupling feature is configured to couple to a second casing pipe.
 3. The casing check valve of claim 1, wherein the housing further comprises: a stop feature disposed on an inner surface of the housing.
 4. The casing check valve of claim 3, wherein the stop feature positions the actuating sleeve in the actuated position.
 5. The casing check valve of claim 3, wherein the stop feature comprises the flapper seat.
 6. The casing check valve of claim 1, wherein the housing further comprises: a stop feature disposed on an inner surface of the housing, wherein the stop feature is disposed where the top portion and the middle portion of the housing body adjoin, wherein the stop feature positions the actuating sleeve in the normal position.
 7. The casing check valve of claim 1, wherein the at least one actuating sleeve coupling feature comprises a plurality of actuating sleeve coupling features.
 8. The casing check valve of claim 7, wherein the actuating sleeve is in the normal position when the at least one first housing coupling feature is coupled to a first actuating sleeve coupling feature of the plurality of actuating sleeve coupling features, and wherein the actuating sleeve is in the actuated position when the at least one first housing coupling feature is coupled to a second actuating sleeve coupling feature of the plurality of actuating sleeve coupling features.
 9. The casing check valve of claim 8, wherein the second actuating sleeve coupling feature is disposed closer to the bottom portion of the housing than the first actuating sleeve coupling feature.
 10. The casing check valve of claim 8, wherein the at least one housing coupling feature is a collet that protrudes from the actuating sleeve body, and wherein the first actuating sleeve coupling feature and the second actuating sleeve coupling feature are recesses having a shape and a size to receive the collet.
 11. The casing check valve of claim 1, wherein the at least one actuating sleeve coupling feature comprises mating threads disposed on the inner surface of the middle portion of the housing body, and wherein the at least one housing coupling feature comprises complementary mating threads disposed on the outer surface of the actuating sleeve body.
 12. The casing check valve of claim 11, wherein the actuating sleeve is in the normal position when the complementary mating threads are coupled to a first portion of the mating threads when the actuating sleeve is in the normal position, and wherein the actuating sleeve is in the normal position when the complementary mating threads are coupled to a second portion of the mating threads when the actuating sleeve is in the actuated position.
 13. The casing check valve of claim 1, wherein the flapper assembly comprises a hinge that moves a flapper between an open position and a closed position.
 14. The casing check valve of claim 13, wherein the bottom portion of the housing body comprises a recessed area, wherein the paddle is positioned within the recessed area when the paddle is in the open position.
 15. The casing check valve of claim 13, wherein the paddle is moved to the open position by the distal extension of the actuating sleeve when the actuating sleeve is in the actuated position.
 16. A casing check valve system for providing isolation within a wellbore, the casing check valve system comprising: a casing string disposed in a wellbore, wherein the casing string comprises a plurality of casing pipe; an operational string comprising an operating tool, wherein the operating tool comprises at least one complementary coupling feature; a casing check valve coupled to a first casing pipe, wherein the casing check valve comprises: a housing comprising: a housing body forming a housing cavity that traverses therethrough, wherein the housing body comprises a top portion, a middle portion, and a bottom portion; at least one actuating sleeve coupling feature disposed on an inner surface of the middle portion of the housing body; a flapper assembly disposed along the inner surface of the bottom portion of the housing body; a flapper seat disposed on the inner surface of the bottom portion of the housing body adjacent to the flapper assembly; and a first casing pipe coupling feature disposed on the top portion of the housing body, wherein the first casing pipe coupling feature couples to a first casing pipe of the plurality of casing pipe; and an actuating sleeve disposed within the housing cavity between an actuated position and a normal position, wherein the actuating sleeve is concentric with and adjacent to the housing, wherein the actuating sleeve comprises: an actuating sleeve body forming an actuating sleeve cavity, inside of which the operational string is disposed; at least one housing coupling feature disposed on an outer surface of the actuating sleeve, wherein the at least one housing coupling feature is removably coupled to the at least one actuating sleeve coupling feature of the housing as the actuating sleeve moves between the actuated position and the normal position; at least one operating tool coupling feature that receives the at least one complementary coupling feature of the operating tool disposed within the sleeve cavity; and a distal extension that extends from a distal end of the actuating sleeve body, wherein the distal extension opens the flapper assembly when the actuating sleeve is in the actuated position, and wherein the distal extension allows the flapper to close when the actuating sleeve is in the normal position.
 17. The system of claim 16, wherein the housing of the casing check valve further comprises: a second casing pipe coupling feature disposed on the bottom portion of the housing body, wherein the second casing pipe coupling feature couples to a second casing pipe of the plurality of casing pipe.
 18. The system of claim 16, wherein the at least one complementary coupling feature is mechanically retractable.
 19. The system of claim 16, further comprising: a control unit; and a control line coupled to the control unit and the at least one complementary coupling feature, wherein the control unit controls hydraulic fluid through the control line to determine a state of the at least one complementary coupling feature.
 20. A method for isolating a section of a wellbore, the method comprising: receiving a coupling feature of an operating tool; repositioning, based on movement of the operating tool in a direction, an actuating sleeve within a housing body from a first position to a second position, wherein repositioning the actuating sleeve from the first position to the second position changes a flapper assembly from a first state to a second state; and releasing, based on continued movement of the operating tool in the direction, the coupling feature of the operating tool. 